// The core ZeroMQ messaging loop. Handles requests and responses // asynchronously using the router socket. Every request is delegated to // a goroutine for maximum concurrency. // // `gozmq` does currently not support copy-free messages/frames. This // means that every message passing through this function needs to be // copied in-memory. If this becomes a bottleneck in the future, // multiple router sockets can be hooked to this final router to scale // message copying. // // TODO: Make this a type function of `Server` to remove a lot of // parameters. func loopServer(estore *eventstore.EventStore, evpubsock, frontend zmq.Socket, stop chan bool) { toPoll := zmq.PollItems{ zmq.PollItem{Socket: &frontend, zmq.Events: zmq.POLLIN}, } pubchan := make(chan eventstore.StoredEvent) estore.RegisterPublishedEventsChannel(pubchan) go publishAllSavedEvents(pubchan, evpubsock) defer close(pubchan) pollchan := make(chan zmqPollResult) respchan := make(chan zMsg) pollCancel := make(chan bool) defer stopPoller(pollCancel) go asyncPoll(pollchan, toPoll, pollCancel) for { select { case res := <-pollchan: if res.err != nil { log.Println("Could not poll:", res.err) } if res.err == nil && toPoll[0].REvents&zmq.POLLIN != 0 { msg, _ := toPoll[0].Socket.RecvMultipart(0) zmsg := zMsg(msg) go handleRequest(respchan, estore, zmsg) } go asyncPoll(pollchan, toPoll, pollCancel) case frames := <-respchan: if err := frontend.SendMultipart(frames, 0); err != nil { log.Println(err) } case <-stop: log.Println("Server asked to stop. Stopping...") return } } }